Integrated: 8223056: Remove Type-Stable-Memory support for Parkers

[David Holmes]

On Fri, 15 Jan 2021 04:35:03 GMT, David Holmes <dholmes at openjdk.org> wrote:

> As per the bug report, once we ensure the calls to unpark() are guaranteed to only occur on a live thread (protected by a ThreadsListHandle) Parkers (the synchronization object underlying java.util.concurrent.LockSupport) no longer need to use type-stable-memory (TSM).
> 
> As a Parker is inherently associated with a single JavaThread, the Parker is now embedded directly in JavaThread, avoiding the need to use new/delete.
> 
> The Parker and PlatformParker classes are now simplified from a memory management perspective. I also made them NONCOPYABLE for good measure. Possibly other constraints could be applied to them such as disallowing new/delete? (Though if we go that far maybe we need a new allocation base type?).
> 
> Testing: tiers 1-3 plus additional test builds
> 
> Thanks,
> David

This pull request has now been integrated.

Changeset: 77a43023
Author:    David Holmes <dholmes at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/77a43023
Stats:     159 lines in 9 files changed: 28 ins; 94 del; 37 mod

8223056: Remove Type-Stable-Memory support for Parkers

Reviewed-by: coleenp, rehn

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PR: https://git.openjdk.java.net/jdk/pull/2089